The present disclosure relates to wireless communication systems, and more particularly to contention resolutions techniques in a wireless network that utilize frequency and/or spatial domains.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless network, for example a Wireless Local Area Network (WLAN), such as a Wi-Fi network (IEEE 802.11) may include an access point (AP) that may communicate with one or more stations (STAs) or mobile devices. The AP may be coupled to a network, such as the Internet, and enable a mobile device to communicate via the network (and/or communicate with other devices coupled to the AP).
In some examples, a mobile device may attempt to access a medium or channel of a network by monitoring the channel status. If the channel is unavailable, the mobile device may defer its access attempt to the channel for a period of time (referred to as backoff operations) and, when the time expires, attempt to access the channel by exchanging request-to-send/clear-to-send (RTS/CTS) messages with an AP. A collision may occur when more than one mobile device ends its waiting period at the same time and attempts to seize the same channel. This collision may result in a loss of the colliding transmissions.
Additionally, when a mobile device successfully accesses the medium at the end of its backoff operation, it may not necessarily utilize the full resources of the medium. For example, a mobile device with a small amount of data to communicate may use one carrier of the channel, may only use the channel for a portion of the frame, etc. According to current implementations, as other mobile devices will not attempt to access the medium until a subsequently free frame, the remaining resources of the medium are underutilized.